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Assessing coral health and resilience in a warming ocean: Why looks can be deceptive
Author(s) -
Wooldridge Scott A.
Publication year - 2014
Publication title -
bioessays
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.175
H-Index - 184
eISSN - 1521-1878
pISSN - 0265-9247
DOI - 10.1002/bies.201400074
Subject(s) - coral , resilience of coral reefs , coral reef , reef , biology , symbiodinium , ecology , symbiosis , coral bleaching , effects of global warming on oceans , climate change , herbivore , resistance (ecology) , ocean acidification , global warming , genetics , bacteria
In this paper I challenge the notion that a healthy and resilient coral is (in all cases) a fast‐growing coral, and by inference, that a reef characterised by a fast trajectory toward high coral cover is necessarily a healthy and resilient reef. Instead, I explain how emerging evidence links fast skeletal extension rates with elevated coral‐algae (symbiotic) respiration rates, most‐often mediated by nutrient‐enlarged symbiont populations and/or rising sea temperatures. Elevated respiration rates can act to reduce the autotrophic capacity (photosynthesis:respiration ratio) of the symbiosis. This restricts the capacity of the coral host to build and maintain sufficient energy reserves (e.g. lipids) needed to sustain essential homeostatic functions, including sexual reproduction and biophysical stress resistance. Moreover, it explains the somewhat paradoxical scenario, whereby at the ecological instant before the reef‐building capacity of the symbiosis is lost, a reef can look visually at its best and be accreting CaCO 3 at its maximum.